Diet Detective: Best strength-training exercises, part 1

This is part of a continuing series on the best strength training exercises. The first in the series is the pull-up.

Expert: James Villepigue, CSCS, author of "The Obstacle Race Training Bible: The No. 1 Resource to Prepare for and Conquer Any Course" (ALPHA, 2012)

Primary body parts: Latissimus dorsi (upper, outer back)

Secondary body parts: Biceps brachii, radialis, serratus, abdominals

Why you should do this exercise: Let's face it, pulling up your body weight is not only cool, it's also amazing for building upper-body strength. It will absolutely help you perform your everyday activities better, and it could even save your life if you ever needed to pull yourself out of a difficult spot. If you've mastered doing machine or cable pull-downs and are looking for a new challenge, pull-downs pale in comparison to the pull-up exercise.

What you need (equipment): You will need some sort of a pull-up bar, but it doesn't necessarily need to be designed just for pull-ups. As long as you have a sturdy and adequate gripping surface, this really is a very versatile exercise.

How to do it: Begin by taking an overhand and shoulder-width grip on the bar. Wrap your thumbs on top of your fingers; this will help to keep your back muscles stimulated while preventing the biceps and forearms from getting too involved in the exercise.

While gripping the bar, bend your knees and cross your ankles so that your feet are off the floor. Contract your abdominal muscles to help sustain your postural alignment throughout the movement.

Stick your chest out while pressing your shoulders downward, which will help isolate the intended back muscles.

Keeping your elbows as wide apart as you can, begin pulling your chest toward the bar. Throughout the movement, keep your head and eyes looking up. Knowing that you must reach your target position at the top of the bar adds that extra push.

When you can no longer move upward while maintaining the proper alignment, consciously focus on squeezing and contracting your back muscles as hard as you can for a moment.

Slowly lower your body while mentally focusing on activating your back muscles. (Your feet shouldn't touch the floor after you lower yourself - you're supposed to do reps before allowing your feet to touch the floor.)

How often should you do it (daily, weekly): If pull-ups are your primary upper-back exercise, you should do them two or three times per week. Training them more often will not give your muscles adequate recovery time.

How many repetitions should you do? The pull-up is a difficult exercise to do. Doing five to 10 reps would be an admirable feat for anyone, be it a mainstream consumer or a bodybuilder. If you can do more than 10 reps with great form, you're awesome!

How you know you're doing it right: You should feel those outer- and inner-back muscles. For outer-back muscle stimulation, focus on the winged looking v-taper muscles located on the outermost lateral portion of the back, running from your rear shoulders down to your hips.

The back muscles closer to the midline of your body and along either side of your spine are the erector spinae muscles. Think of these as the muscles that allow your spine to extend and help maintain spinal stability. You also have upper-back muscles composed of the trapezius, levator scapulae and rhomboids. All of these muscles will be working hard both as you pull up and also as you slowly lower back down. Your back muscles should both look and feel fuller, and you may very well feel a lactic acid burn as you progress through your repetitions. As you reach your last rep, your back muscles/arms will undoubtedly feel exhausted. If they don't, check your form.

How not to do it: Avoid swinging at all costs. If you must swing and build momentum to pull yourself up, you should either have a partner spot you through your sticking points or consider doing pull-downs until you've built up enough strength to do a proper pull-up.

Who should not do this exercise: Avoid this exercise if you have any shoulder or neck problems. If you suffer from a lower-back injury or pain, avoid hyperlordosis, that overarching of the lower back. If you are overweight or obese, see if you can manage pulling yourself up with the assistance of a qualified trainer.

Most common mistakes: Many people use their feet to jump up or build momentum. Avoid jerking the body simply to pull yourself up. Focus on pulling your body up in a swift yet smooth motion.

What's the least amount I can do and still get a benefit (reps and days per week): Even if you were to throw pull-ups into your workout only once every two weeks, you could still see remarkable results. But also, remember the use-it-or-lose-it adage. If you master pull-ups and then stop doing them for too long, there's a good chance you'll lose the ability to do them effortlessly.

This exercise is for: Anyone looking for an incredibly effective and challenging upper-body exercise. The pull-up is a compound movement that stimulates a majority of the upper body's musculature, including the back, shoulders, abdominals/core, biceps and forearms.

This is a taxing exercise, so beginners or people who far exceed their target weight may want to start out with pull-downs on a lat machine until they develop enough strength.

Charles Platkin is a nutrition and public health advocate and founder of DietDetective.com.